Leases (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 1989	Dec. 31, 1988
Rent expense		$ 47,800,000	$ 53,100,000	$ 44,400,000
Entergy Arkansas [Member]
Rent expense		6,200,000	7,500,000	8,000,000
Payments For Railcar Operating Lease		2,800,000	4,000,000	3,400,000
Regulatory Assets		$ 138,300,000	176,900,000
Purchased Percentage Of Capacity And Energy Based On Agreement		17.10%
Entergy Louisiana [Member]
Portion of Waterford 3 purchase price satisfied through issuance of debt	$ 52,000,000
Rent expense		$ 20,200,000	23,000,000	17,800,000
Payments For Railcar Operating Lease		400,000	300,000	$ 300,000
Cash payment representing the purchase price to acquire the undivided interests in Waterford 3	$ 60,000,000
Net regulatory liability related to sale and leaseback transaction		$ 18,800,000	32,400,000
Purchased Percentage Of Capacity And Energy Based On Agreement		26.90%
Entergy Louisiana [Member] | Purchased Power Agreement [Domain]
Percentage Of Capacity And Energy Purchased Under Purchased Power Agreement		50.00%
Entergy Louisiana [Member] | Waterford 3 [Member]
Sale and lease back transaction amount						$ 353,600,000
Implicit rate of future minimum lease payments				8.09%
Liability related to undivided interests in Waterford 3					$ 62,700,000
Reduction in liability related to undivided interest in Waterford 3					2,700,000
Reduced liability related to undivided interests in Waterford 3					$ 60,000,000
Minimum Lease Payments, Sale Leaseback Transactions				$ 57,500,000
Interest Portion of Minimum Lease Payments, Sale Leaseback Transactions				2,300,000
Entergy Mississippi [Member]
Rent expense		$ 4,600,000	5,600,000	4,000,000
Regulatory Assets		$ 63,500,000	91,600,000
Purchased Percentage Of Capacity And Energy Based On Agreement		31.30%
Oil Tank Facilities Lease Payments		$ 100,000	1,600,000	1,600,000
Entergy New Orleans [Member]
Rent expense		2,500,000	2,500,000	900,000
Regulatory Assets		$ 49,300,000	44,800,000
Purchased Percentage Of Capacity And Energy Based On Agreement		24.70%
Entergy Texas [Member]
Rent expense		$ 3,100,000	3,400,000	2,800,000
Regulatory Assets		50,900,000	55,200,000
Capacity expense under purchase power agreements accounted for as operating leases		$ 30,500,000	34,100,000	26,100,000
Entergy Texas [Member] | Purchased Power Agreement [Domain]
Percent of minimum payments		100.00%
System Energy [Member]
Rent expense		$ 1,900,000	2,200,000	$ 1,600,000
Regulatory Assets		76,400,000	67,900,000
System Energy [Member] | Grand Gulf [Member]
Year Two		17,188,000
Sale and lease back transaction amount							$ 500,000,000
Regulatory Assets		0
Net regulatory liability related to sale and leaseback transaction		55,600,000	$ 55,600,000
Minimum Lease Payments, Sale Leaseback Transactions		309,377,000
Interest Portion of Minimum Lease Payments, Sale Leaseback Transactions		$ 275,025,000